Maldivia triunguiculata (Borradaile), a xanthid crab, lives within
chambers in the skeletons oflive Porites lobata corals. The chamber openings are
readily recognizable on the live surfaces of P. lobata heads, and chambers
penetrate into coral skeletons up to 5.5 cm. Crabs inhabited an average of
85 percent of the chambers investigated. Occupied chambers contained males
or females, but never more than one crab per chamber. Areal density of
M. triunguiculata on P. lobata increased with increasing coverage of the reef by
the live coral, indicating a strong association between the two species. Although
M. triunguiculata may occur on dead coral reef, this study indicates that it is more
frequently found in live P. lobata.